A coded optical beacon is currently being provided on automatic command to line-of-sight anti-tank guided missile systems, which provides a unique missile signature for automatic tracking and guidance. This signature should provide discrimination against normal background interference such as fires, horizon, glare, reflection, etc. and; discrimination against deliberate false targets such as flares, searchlights, and other optical jammers, however, these optical signatures provide a relatively low frequency signal output and as therefore susceptible to false targets (optical jammers) having frequencies in this low frequency range.
Jamming sources for optical beacons include Tungsten flare and Xenon arc lamps. These lamps are high average intensity jammers at relatively low frequencies. For example, the frequency response of the Xenon arc lamp is a function of lamp size and current. Increasing the lamp size and increasing input power level reduces the frequency response of the optical output of the lamp. Xenon and other relative low frequency jammers offer little significant countermeasures threat to a high frequency coded system. Typically, test results of a 75 watt Xenon arc lamp indicate that approximately 100 KHz can be construed to be a maximum boundary of relative effectiveness for Xenon jammers. Since these lamps and other similar optical jammers are less efficient at higher frequencies, operation of an optical beacon at a relatively high frequency is desirable when the high frequency exceeds the maximum effective boundry of the jammers. High frequency operation of missile beacons has been prohibitive in the past because of the physical characteristics of light emitting devices.